1. Field of the Invention
The present invention relates to an apparatus for mixing a first liquid and a second liquid in a predetermined ratio for the manufacture of cooling beverages or in industry generally.
2. Description of the Prior Art
FIG. 1 shows a construction of a prior art liquid mixing apparatus for use in a manufacturing process of a cooling beverage.
Water to be processed for the manufacture of the cooling beverage is supplied through an inlet 1 to a tank 4 for use in the evacuation of oxygen. A liquid level in the tank 4 is controlled to be maintained to a predetermined level by a water control valve 2.
The tank 4 may be of a packed tower type, a wetted-wall column type, or a tray tower type. A vacuum unit 3 is coupled to the tank 4 so that oxygen contained in the water to be processed is evacuated under vacuum. The evaucated water is sent out from an outlet pipe 5 through a check valve 7 and a water pipe 8 to a water tank 10 by means of a water pump 6.
An inlet valve 9 serves to always maintain constant a level of the evacuated water supplied to the water tank 10. A syrup supply valve 12 serves to maintain constant a level of syrup for use in the manufacture of a cooling beverage in a syrup tank 13 supplied from a supply port 11.
Water in the tank 10 and syrup in the tank 13 are applied with an atmospheric pressure or are pressurized by the same pressure if necessary.
The evacuated water is supplied from the water tank 10 through a water measuring valve 14 and a water mixing valve 15 to a mixing tank 18 having a pressure therein maintained at atmospheric pressure. The amount of water flowing into the mixing tank 18 is substantially propotional to an opening of the water measuring valve 14 since the pressure applied to the water tank 10 is maintained constant and a difference between a level of the water tank 10 and a level of the mixing tank 18 is always maintained approximately constant.
Syrup is supplied from the syrup tank 13 through a syrup measuring valve 16 and a syrup mixing valve 17 to the mixing tank 18. The amount of syrup flowing into the mixing tank 18 is substantially propotional to an opening of the syrup measuring valve 16 in the same manner as that of water since the pressure applied to the syrup tank 13 is maintained constant and a difference between a level of the syrup tank 13 and a level of the mixing tank 18 is always maintained approximately constant.
The mixed liquid in the tank 18 is sent out with pressure by a mixing pump 19 through a control valve 20 to a next process. The control valve 20 is constructed to automatically control the level of the mixing tank 18 to a constant level.
The above liquid mixing apparatus has the following problems:
(1) Since the evacuation tank 4 is independent, the evacuation tank and its space are necessary.
(2) The pump 6 for the evacuated water and the check valve 7, the pipe 8 and the inlet valve 9 for sending out water are necessary.
(3) It is required to control the liquid levels in four tanks, viz., the evaucation tank 4, the water tank 10, the syrup tank 13 and the mixing tank 18.
(4) Since the mixing pump 19 is provided with the control valve 20 for maintaining constant the liquid level in the mixing tank 18, the mixing pump 19 is required to have a relatively large capacity.